Improved platelet adhesion under flow conditions in left ventricular assist device patients treated with recombinant von Willebrand factor concentrate

Introduction Left ventricular assist devices (LVADs) are an established treatment for advanced heart failure and are used as bridge-to-transplant, recovery, or destination therapy. The Heartmate 3®​ (HM3) is the latest device. Gastrointestinal bleeding (GIB) is a common serious complication associated with LVAD use. It is caused by factors such as reduced pulsatility, arteriovenous malformations, acquired von Willebrand syndrome (aVWS), and anticoagulation. Treating GIB is challenging; VWF/FVIII therapy is possible but rarely used. Our study examined whether LVAD patient platelets adhere to and activate properly on VWF-coated surfaces and among different VWF concentrates. Method We studied 14 patients with HM3 LVAD and 20 healthy donors. Platelet adhesion to VWF was tested using a microfluidic flow chamber. The VWF concentrates examined were Haemate P®​, Wilate®​, Willfact®​ (plasma-derived, pdVWF) and recombinant Veyvondi®​ (rVWF). The chambers were coated overnight and PPACK-anticoagulated blood was pumped at 2000 s–¹ through the chamber. Adhered platelets were stained and quantified by immunofluorescence, and platelet activation was assessed by flow cytometry [ 1 ] [ 2 ] [ 3 ] [ 4 ] [ 5 ] [ 6 ] [ 7 ] [ 8 ] [ 9 ]. Results Our results show that platelets from LVAD patients adhered significantly better to the Veyvondi®​-coated surface after one min compared to Haemate P®​ (p